Punching device having a spring biased stripper



March 5, 1963 A. k. SCHOTT 3,079,824

PUNCHING DEVICE HAVING A SPRING BIASED STRIPPER Filed Aug. 9, 196C)illlllllill S,e7,82 UNCHJNG SE1-J CE H1/1N@ A SPRNG d1-'ASEE STRIPPERArthnr K. Schott, Kenmore, NDL, assigner to Houdaille industries, inc.,Burials, NX., a carpet-ation of Michi- 9, 196%, Ser. No. 48,376 6Claims. {CL 83-14t3) rlhis invention relates generally to punchingdevices of the unitized type, and more specically to improved punchguidance and retention means incorporated therein.

Although the principles of the present invention may be included invarious punching devices, a particularly useful application is made inpunching devices of the unitized or subpress type in which a die iscarried in alignment with a punch and guide assembly by a C-shaped rarneor holder. lunching devices of this general type are known in the art,and have been provided with punches and dies whose cutting edges areboth circular and shaped (nonchcular). Devices oi this type have alsobeen provided which include a guide button which has a close sliding twith the working end of the punch.

'It is apparent that it is more expensive to provide and operate devicesof this type where the punch tip is provided with guidance means thanwhen such means are omitted, and yet when the highest quality ofpunching is required, it has been found necessary to employ punch tip orworking end stripping means. ln the past, this has necessitated the useof two separate devices, one which incorporates the guided tip means,and the other which, for economy reasons, omits the same.

it is also known in the art that shaped punches and dies requireindexing or keying to maintain them accurately in alignment so as topreclude any possible relative angular movement.

rEhe greatest manufacturing economies can be obtained when a singleholder may be used for a variety of sizes and shapes of punches anddies, and to this end, it is preferable that the punch and guideassembly thereof be removable for replacement purposes. Such assemblytypically is slidable in the upper arm or the holder and is maintained araised or ele ated position by appropriate lifting means. Means havepreviously been provided for holding such assembly in the holder in amanner that such assembly can reciprocate, but yet not inadvertentlyescape, for example during handling thereof.

Accordingly, it is an object of the present invention to provide apunching device of the type described which is provided with improvedmeans for guiding and angularly locating the punch and guide assemblythereof.

A further object of the present invention is to provide a punchingdevice of the type described in which there is embodied improved meansfor retaining the punch and guide assembly thereof.

Yet another object of the present invention is to provide punch andguide assembly retaining and guiding means which permits use of either around punch or a shaped punch alternatively in the same assembly.

A still further object of the present invention is to provide a punchand guide assembly for a punching device of the type described in whicha stripper button may be selectively included or omitted in accordancewith work requirements.

Many other advantages, features and additional objects of the presentinvention will become manifest to those versed in the art upon makingreference to the detailed description and the accompanying sheet ofdrawings in which a preferred structural embodiment incorporating theprinciples of the present invention is shown by way of illustrativeexample.

didnt On the drawings:

FIGURE l is a side elevation view, partly in crosssection, of a punchingdevice equipped with improved punch guidance and retention meansprovided in accordance with the principles of the present invention;

FIGURE 2 is a top view or the punching device shown in FIGURE l;

FIGURE 3 is a fragmentary cross-sectional view taken along line IlI--IIIof FIGURE l;

FlGURE 4 is an enlarged elevational view of a novel locating pinprovided in accordance with the principles of the present invention; and

FlGURE 5 is a perspective view of a novel and stripping guide buttonemployed in the device shown in FIGURE 1.

As shown on the drawings:

The principles of this invention are particularly useful when embodiedin a punching device assembly such as illustrated in FIGURE 1, generallyindicated by the numeral 1t).

The punching device 10 includes a C-shaped frame or holder 11 having anupper arm 12 and a lower arm 13 in which there are respectivelysupported a punch and guide assembly 14 and an apertured die 15.

The upper arm 12 has a bore 16 in which the punch and guide assembly 14is reciprocably supported and guided. To this end, the upper arm 12 isprovided with a circular opening 17 which intersects the bore 16 andpreferably passes through the holder on both sides thereof as shown sothat it is open at both ends to removably receive a locating pin 18vwhich also is of circular cross-section and which is rotatably disposedin the opening 17 as shown.

The lower arm 13 has a bore 19 in which the die 15 is received, the die15 having an aperture 2G aligned with the working end 21 of a punch 22.The die 15', especially if the opening 2d is shaped, is provided with aslot 23 which is registerable with a second circular opening 24 disposedin the lower arm 13, and intersecting the bore 19 in the manner that theopening 17 intersects the bore 16 of the upper arm 12. Within theopening 24 there is provided a locating pin 25, the inner end of whichis received within the slot 23 for lixing the angular position of thedie 1S. As shown in FIGURE 3, the working end 21 of the punch 22, andalso the aperture 2b in the die 15, are of shaped or oval configuration,the oval configuration being used here to be representative of allnon-circular shapes of working tips of punches and die apertures. Toretain the die 15 in position, a setscrew 26 shown in FIGURE 2 isthreadably received through an end or forward face on the lower arm 13.

The punch and guide assembly includes an elongated sleeve 27, an nnularupper collar 23 slidably disposed at the upper end of the sleeve 27, alower annular collar 29 disposed about the lower end of the sleeve 27,and a stripping spring 3d extending about the sleeve 27 and actingbetween the upper collar 2S and the lower collar 29 to bias such collarsapart. The upper collar 2S has an outer surface 31, and the lower collar29 has an outer surface 32 which are in direct slidable engagement withthe upper arm 12 within the bore 16 thereof. The lower collar 29 has aslot 33 in its outer surface 32 which is deiined by a pair ofconfronting Walls which extend parallel to the direction in which thepunch and guide assembly 14 is reciprocable. The slot 33 registers withthe opening 17 so that the inner end of the locator pin 18 is closelyand slidably received within the slot 33. The lower collar 29 is furtherprovided with a pair of concentric recesses 34, 3S which opendownwardly, the recess 35 being internally slotted to r ceive a snapring. Thus the lower collar 29 is provided with the recess 35 forremovably receiving and retaining a guide and/ or stripper button 36shown in de- `in place therein by a removable snap ring 38. The openingin the guide button 36 has a configuration corresponding to the workingend of the punch 2.1, and has a close sliding tit therewith to enableaccurate stripping of the workpiece from the working end 21 and forguiding the Same.

Ihe sleeve 27 is grooved at its ends and receives an-additional pair ofsnap rings 39, 40 axially outwardly of lshoulders of the collars 28, 29respectively for limiting the distance apart which the spring 30 canurge such collars, the stripping spring 30 thereby being held in partialcompression. Y A locking pin 42 coacts between vthe lower collar 29 andthe sleeve 2'7 to preclude axial or angular relative movementtherebetween. Thus the lower end of the stripping spring 30, the lowercollar- 29, and the sleeve 27 are thus slidable as a unit and are guidedby the locating pin 18 for such movement with respect tothe holder 11.

' The punch and guide assembly 14 further includes the `punch 22 whichhas a head 43 which projects from the -upper collar 28, the body of thepunch 22 being directly slidable within the sleeve 27. The head 43 ofthe punch 22 has a peripheral slot which registers with an internal slotin the upper collar 28, there being a manually removable snap ring 44received therein. The side of the collar 28is cut away-for a few degreesso that the free Vends'of the spring can project horizontally therefromfor manual grasping thereof as shown. When the snap ring 44 iscompressed, the, punch 22 and snap ring 44 may be vremoved as a unitsince the ring 44 is received to the extent necessary within the head43. A lifting spring 45 cooperates with the upper surface of the upperarm 12 and a groove in the outer surface 31 of the upper collar 28 toprovide an upward biasing or lifting force to the punch and guideassembly 14.

The punch and guide assembly 14 is provided with an upwardly directedshoulder 46 carried on the upper collar 28, which shoulder 46 isdirected in the direction of the bias fromthe spring 45. To cooperatetherewith in retaining the punch and guide assembly 14 and in holdingthe lifting spring 45 in partial compression, there is provided anelongated stop plate 47 which is disposed and supported on the uppersurface of the upper arm 12 of the holder 11. The stop plate 47overhangs a portion of the bore 1 6 so that its lower surface is engagedby the vshoulder 46 to limit upward movement of the punch and guideassembly 14. As best seen in FIGURE 2, the stop plate 47 has at one endan aperture 48 and at the other end a laterally directed slot 49, a pairof screws 50, 50 respectively extending through the aperture 48 and theslot 49 to hold the elongated stop plate securely in position. When thescrews 50 are loosened, the plate 47 may be pivoted about the aperture48 for removal of the punch and guide assembly 14 as a unit.

The body of the punch 42 is provided with a recess which receives aWoodruff key 51 which projects therefrom into an elongated slot 52 inthe sleeve 27. The sleeve 27 is provided with an additional slot 53 bestseen in FIGURE 3, as is also the die 15, so that the shaped punch 22 maybe selectably positioned in either of two angular positions.

Referring again to FIGURE 4, it will be noted that the pin 1S has a pairof fiat portions 54, which are the portions thereof which snuglyslidably tit within the slot 3-3 or" the lower collar 29. At the otherend or" the pin 18, and in the corresponding end of the locating pin2.5, there is provided a pair ofv spaced integral axially directedbifurcations 55, 56 at least one of which is resilient and which have. afree position slightly greater than the 'size ofthe opening 17. Forexample, I have found that if the dimension across the bifurcations isabout .005 inch greater than the diameter of` the opening 17, thelocating vguide or stripper button 36, and die 15 may be rotated toan-angularly spaced position where similar guidance is provided.Further, where another size or conguration is desired, these samecomponents may be easily removed and replaced. Even though such be done,all other components can continue to be used. Further, if less exactingwork is required, the guide button 36 may be removed readily by the useof the device. It is also apparent that punch, die, and guide buttoncomponents may be entJ ployed which are adapted to make circularopenings. Furthermore, the locating pins 1S, 25 may be retracted bymeans entering the opposite end of the openings 17 and 24 respectivelyso that the holder will receive a punch and guide assembly which is notprovided with a slot 33 and a die which is not provided with a slot 23.Thus the instant combination of punch guidance and retention means isespecially versatile, so that one assembly may be used in a number ofapplications.

Although various minor modilications might be suggested by those versedin the art, it should be understood that I wish to embody within thescope of the patent warranted hereon all such embodiments as reasonablyand properly come within the scope of my contribution to the art.

I claim as my invention:

1. A punching device comprising in combination: a C-shaped frame havingupper and lower arms with axially aligned bores therein; an apertureddie removably secured in the bore of the lower of said arms; a punch andguide `assembly recipro-cably disposed in the bore of the upper of saidarms, said assembly including an elongated punchguide sleeve, an upperannular collar slidably surrounding the upper end of said sleeve and alower annular vcollar surrounding the lower end of said sleeve, astripping spring means extending about said sleeve and biasing saidcollars apart, a pair of snap rings each carried by one end of saidsleeve and acting against said collars to hold said stripping springmeans in partial compression, said collars each having a surface indirect slidable engagement with said upper arm, a punch slidablyreceived within said sleeve and guided thereby and having a head enddisposed in and projecting from said upper collar, a manually removablesnap ring securing said head end to said upper collar, said punch havinga working end adapted to cooperate with said die, and said lower collarhaving a downwardly directed internal recess` defining a downwardlydirected annular shoulder within the axial limits of the working end ofthe punch, said recess being adapted to receive and removably retain astripper button at said Working-end of said punch; and a lifting springcoacting between said upper arm and said upper collar to bias saidassembly away from said die.

2. A punching device comprising in combination: a C- shaped frame havingupper and lower arms with axially aligned bores therein; an apertureddie removably secured in the bore of the lower of said arms; a punch andguide assembly reciprocably disposed in the bore of the upper of saidarms, said assembly including an elongated punchguide sleeve, 'an upperannular collar slidably surrounding the upper end of said sleeve and alower annular collar surrounding the lower end of said sleeve, astripping spring means extending about said sleeve and biasing saidcollars apart, a pair of snap rings each carried by one end of saidsleeve and acting against said collars to hold said stripping springmeans in partial compression, said collars each having a surface indirect slidable engagement with said upper arm, a punch slidablyreceived within said sleeve and having a head end disposed in andprojecting from said upper collar, a manually removable snap ringsecuring said head end to said upper collar, said punch having a workingend adapted to cooperate with said die, said lower collar having adownwardly directed internal recess defining a downwardly directedannular shoulder within the axial limits of the working end of thepunch, an annular stripper button received within said recess and havinga lit for cooperating with said working end of said punch, and meansremovably securing said stripper button in said recess; and a liftingspring coacting between said upper arm and said upper collar to biassaid assembly away from said die.

3. A punching device comprising in combination: a C- shaped frame havingupper and lower arms with axially aligned bores therein; an apertureddie removably secured in the bore of the lower of said arms; a punch andguide assembly reciprocably disposed in the bore of the upper of saidarms, said assembly including an elongated punchguide sleeve, an upperannular collar slidably surrounding the upper end of said sleeve andhaving a shoulder within the bore of the upper arm directed away fromsaid die, and a lower annular collar surrounding the lower end of saidsleeve, stripping spring means extending about said sleeve and biasingsaid collars apart, a pair of snap rings each carried by one end oi saidsleeve and acting against said collars to hold said stripping springmeans in partial compression, said collars each having a surface indirect slidable engagement with said upper arm, a punch slidablyreceived within said sleeve and guided thereby and having a end disposedin and projecting from said upper collar, a manually removable snap ringsecuring said head end to said upper collar, said punch having a workingend adapted to cooperate with said die, and said lower collar having adownwardly directed internal recess defining a downwardly directedannular shoulder within the axial limits of the working end o the punch,said recess being adapted to receive and removably retain a stripperbutton at said working-end of said punch; an elongated stop platedisposed on the upper surface of the upper of said arms in overhangingrelation to the bore thereof for engagement with tiret-mentioned shouiler, said plate being apen tured at one end and laterally slotted at theother end; a or" screws, one extending through the plate aperture andthe other through the plate slot and normally secursaid plate in fixedposition to limit upward movement of said first-mentioned shoulder, theplate slot being so arranged that said screws, when each is onlypartially released, enable pivoting of said plate about the axis of theaperture thereof while said assembly is in said upper bore to facilitatereplacement of said assembly; and a lifting spring coacting between saidupper arm and said upper collar to bias said assembly away from saiddie.

4. A punching device comprising in combination: a C-sha; ed trarnehaving upper and lower arms with axiaily aligned bores therein; anapertured die removably secured in the bore of ythe lower of said arms;a punch amd guide assembly reciprooably disposed in the bore of Lne uper oi said arms, said assembly including an elongated punch-guidesleeve, an upper annular collar slidably surrounding the upper end ofsaid sleeve land a lower annular collar surrounding the lower end ornsaid sleeve, stripping spring means extending about said sleeve andbiasing said `collars apart, a pair or snap rings each carried by `oneend of sleeve and acting against said collars to hold said strippingspring means in partial compression, said colims each having an outersurface in direct sl-idahle engagement with said upper arm, a. punchslidably received within said sleeve and guided thereby and having ahead end disposed in and projecting from said upper collar, a manuallyremovable snap ring securing said head end to said upper collar, saidpunch naving a working end adapted to cooperate with die, and said lowercollar having a downwardly directed internal rec-ess defining adownwardly directed annular shoulF der within the axial limits of theworking end of the punch, Said recess being adapted to receive andremovably retain a stripper button at said working end of said punch;said lower collar having means defining a slot opening into said outersurface and extending parallel to the direction of the assemblyreciprocation; said upper arm having a circular opening intersectingsaid bore at said slot; a locating pin disposed in said opening, one endof said pin having a snug slidable tit with said lower collar withinsaid slot, and the other end of said pin having a circular crossIsection defined by a pair of spaced integral axially directedbifurcations both of which are entirely disposed in said opening, atleast one of said bifurcations being resilient and having a freeposition from which it is returnably dellected by said frame to sm'dcircular cross section while in said opening for retaining said pintherein against both angular and linear movement; a lifting springcoasting between Said upper arm and said upper collar to bias saidassembly away from said die.

5. A punching device comprising in combination: a C-shapcd frame havingupper and lower arms with axially aligned bores therein; an apertureddie removably secured in the bore of the lower of said arms; a punch'and guide assembly reciprocably disposed in the bore of the upper ofsaid arms, said assembly including an elongated punch-guide sleeve, anupper annular collar slidably surrounding tl e upper end of said sleeveand a lower annular collar surrounding the lower end of said sleeve,stripping spring means extending about said sleeve and biasing saidcollars apart, a pair of snap rings each carried by one end of saidsleeve and acting against said collars to hold said stripping springmeans in partial compression, said collars each having an outer surfacein direct slidable engagement with said upper arm, a punch slidablyreceived within said sleeve and guided thereby and having a head enddisposed in and projecting from said upper collar, a manually removablesnap ring securing said head end to said upper collar, said punch haivnga working end adapted to cooperate with said die, and said lower collarhaving a downwardly directed internal recess detining a downwardlydirected annular shoulder within the axial limits of the working end ofthe punch, said recess being adapted to receive and removaoly retain astripper button at said working end of `said punch; said lower collarhaving means defining a slot opening into said outer surface andextending parallel to the direction of the assembly reciprocation; saidupper arm having a circular opening intersecting said bore at said slot;a locating pin having a circular cross section rotatably and slidablydisposed in said opening, the inner end of said pin being receivedwithin said slot, and having a pair of dat portions snugly and slidablyin engagement with opposite walls of said sl and the other end of saidpin having a circular cross section de fined by a pair of integralaxially directed bifurcations spaced from each other for reception of arotating tool therebetween and both of which are entirely disposed iusaid circular opening, at least one of said bifurcations being resilientand having a free position from which it is returnably deflected by saidupper arm to said circular cross section while in said opening forretaining said pin therein against both angular and linear movement; anda lifting spring coacting between said upper arm and said upper collarto bias said assembly away from said die.

6. A punching device comprising in combination: a G-shaped frame havingupper and lower arms with axF ially aligned bores therein; an apertureddie removably secured in the bore of .the lower ol Said arms; a punchand guide assembly reciprocably disposed in the bore of the upper ofsaid arms, said `assembly including an elongated punch-guide sleeve, anupper vannular collar slidably surrounding the upper end of said sleeveand a lower lannular collar surrounding the lower end of said sleeve,stripping spring means extending about said sleeve and biasing Saidcollars apart, a pair of snap rings each carried by one end of saidsleeve and acting against said coll-ars to hold said stripping springmeans in pai-tial compression, said collars each having an Outer surfacein 'direct sldable engagement with said upper arrn, a punch slidablyreceived wi-thin said sleeve and guided thereby and having a head enddisposed in and projecting from said upper collar, a manually removablesnap ring securing said head end to said upper collar, said punch havinga working end adapted lto cooperate with said die, and said lower collarhaving a downwardly directed internal recess defining a downwardlydirected annular shoulder within Ithe axial limits of the working end ofthe punch, said recess being yadapted 'to receive and removably retain.a stripper button at said working end of said punch; at least one ofsaid assembly yand said die having a slot on its outer surface extendingparallel to the direction of the reciprocation of said assembly; saidframe 'having a circular opening open at both ends, one end of saidopening being aligned with said slot; a locating pin disposed in saidopening, one end of said pin having a snug it within said slot, and theother end of said pin har/ing a circular cross sec-tion defined by apair of spaced integral yaxially directed bifurcations both of which areentirely disposed in said opening, at least one of said bifurcationsbeing resilient and having a free posinion from which it is returnablydeflected by said frame to said circular cross section While in saidopeningfor retaining said pin therein against Iboth angular and linearmovement; and a lifting spring coacting between said upper arm and saidupper collar to bias saidassenibly away from said die. i

References Cited in the iile of this' patent UNITED STATES PATENTS1,886,177 @airing Nov. 1, 1932 1,939,478 Whistler Dec. 1 2, 19331,949,817 Stoneield Mar. 6, 1934 2,017,247 Hodge Oct. 15, 1935 2,320,205Whales May 25, 1943 2,397,325 Newcomb Mar. 26, 1946 2,882,971 BennettApr. 2l, 1959 FOREIGN PATENTS 411,077 Germany Mar. 10, 1925

1. A PUNCHING DEVICE COMPRISING IN COMBINATION: A C-SHAPED FRAME HAVINGUPPER AND LOWER ARMS WITH AXIALLY ALIGNED BORES THEREIN; AN APERTUREDDIE REMOVABLY SECURED IN THE BORE OF THE LOWER OF SAID ARMS; A PUNCH ANDGUIDE ASSEMBLY RECIPROCABLY DISPOSED IN THE BORE OF THE UPPER OF SAIDARMS, SAID ASSEMBLY INCLUDING AN ELONGATED PUNCHGUIDE SLEEVE, AN UPPERANNULAR COLLAR SLIDABLY SURROUNDING THE UPPER END OF SAID SLEEVE AND ALOWER ANNULAR COLLAR SURROUNDING THE LOWER END OF SAID SLEEVE, ASTRIPPING SPRING MEANS EXTENDING ABOUT SAID SLEEVE AND BIASING SAIDCOLLARS APART, A PAIR OF SNAP RINGS EACH CARRIED BY ONE END OF SAIDSLEEVE AND ACTING AGAINST SAID COLLARS TO HOLD SAID STRIPPING SPRINGMEANS IN PARTIAL COMPRESSION, SAID COLLARS EACH HAVING A SURFACE INDIRECT SLIDABLE ENGAGEMENT WITH SAID UPPER ARM, A PUNCH SLIDABLYRECEIVED WITHIN SAID SLEEVE AND GUIDED THEREBY AND HAVING A HEAD ENDDISPOSED IN AND PROJECTING FROM SAID UPPER COLLAR, A MANUALLY REMOVABLESNAP RING SECURING SAID HEAD END TO SAID UPPER COLLAR, SAID PUNCH HAVINGA WORKING END ADAPTED TO COOPERATE WITH SAID DIE, AND SAID LOWER COLLARHAVING A DOWNWARDLY DIRECTED INTERNAL RECESS DEFINING A DOWNWARDLYDIRECTED ANNULAR SHOULDER WITHIN THE AXIAL LIMITS OF THE WORKING END OFTHE PUNCH, SAID RECESS BEING ADAPTED TO RECEIVE AND REMOVABLY RETAIN ASTRIPPER BUTTON AT SAID WORKING-END OF SAID PUNCH; AND A LIFTING SPRINGCOACTING BETWEEN SAID UPPER ARM AND SAID UPPER COLLAR TO BIAS SAIDASSEMBLY AWAY FROM SAID DIE.